Hi, I'm using the TMS320DM642 and need to configure the registers of a video decoder thanks to the I2C module. I read all the documentations TI provides and there still remain questions. I hope someone will help me. 1) When we use the I2C_start() function does it test the NACK bit ? Apparently no! 2) Why do they never test the NACK bit ? 3) When we set a value in the I2CDXR register is this value automatically sent ? The I2CXRDY bit indicates that the data has been copied from the DXR register to the XSR one but not if the whole data have been sent, am i wrong ? 4) What is the interest of the ARDY bit ? Thanks a lot.
TI TMS320DM642, I2C module and APIs
Started by ●March 23, 2005
Reply by ●March 24, 20052005-03-24
Up ! phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503222359.7407c0e8@posting.google.com>...> Hi, > > I'm using the TMS320DM642 and need to configure the registers of a > video decoder thanks to the I2C module. > > I read all the documentations TI provides and there still remain > questions. I hope someone will help me. > > 1) When we use the I2C_start() function does it test the NACK bit ? > Apparently no! > 2) Why do they never test the NACK bit ? > 3) When we set a value in the I2CDXR register is this value > automatically sent ? The I2CXRDY bit indicates that the data has been > copied from the DXR register to the XSR one but not if the whole data > have been sent, am i wrong ? > 4) What is the interest of the ARDY bit ? > > Thanks a lot.
Reply by ●March 29, 20052005-03-29
UP! phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503240756.7298d506@posting.google.com>...> Up ! > > phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503222359.7407c0e8@posting.google.com>... > > Hi, > > > > I'm using the TMS320DM642 and need to configure the registers of a > > video decoder thanks to the I2C module. > > > > I read all the documentations TI provides and there still remain > > questions. I hope someone will help me. > > > > 1) When we use the I2C_start() function does it test the NACK bit ? > > Apparently no! > > 2) Why do they never test the NACK bit ? > > 3) When we set a value in the I2CDXR register is this value > > automatically sent ? The I2CXRDY bit indicates that the data has been > > copied from the DXR register to the XSR one but not if the whole data > > have been sent, am i wrong ? > > 4) What is the interest of the ARDY bit ? > > > > Thanks a lot.
Reply by ●March 31, 20052005-03-31
Hello ???!!! phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503282302.2729fa7a@posting.google.com>...> UP! > > phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503240756.7298d506@posting.google.com>... > > Up ! > > > > phuture_project@yahoo.fr (phuture_project) wrote in message news:<25fe518f.0503222359.7407c0e8@posting.google.com>... > > > Hi, > > > > > > I'm using the TMS320DM642 and need to configure the registers of a > > > video decoder thanks to the I2C module. > > > > > > I read all the documentations TI provides and there still remain > > > questions. I hope someone will help me. > > > > > > 1) When we use the I2C_start() function does it test the NACK bit ? > > > Apparently no! > > > 2) Why do they never test the NACK bit ? > > > 3) When we set a value in the I2CDXR register is this value > > > automatically sent ? The I2CXRDY bit indicates that the data has been > > > copied from the DXR register to the XSR one but not if the whole data > > > have been sent, am i wrong ? > > > 4) What is the interest of the ARDY bit ? > > > > > > Thanks a lot.
Reply by ●March 31, 20052005-03-31
Some might have noticed that nobody here seems to know anything about this issue. Others obviously didn't. Try the TI hotline. Regards Andor
Reply by ●March 31, 20052005-03-31
phuture_project wrote:> I'm using the TMS320DM642 and need to configure the registers of a > video decoder thanks to the I2C module.Don't know if it helps, but since no-one else has replied, this is the code that TI use to talk to the SAA7115 on the DM642 EVM - #define I2CDELAY(iterations) { \ volatile Int j; \ for(j = 0; j < iterations; j ++); \ } #define DELAY_TIME 1000 static const I2C_Config EVM642VIDEOIIC_Config = { 0, /* master mode, i2coar; */ 0, /* no interrupt, i2cimr; */ (20-5), /* scl low time, i2cclkl; */ (20-5), /* scl high time,i2cclkh; */ 1, /* configure later, i2ccnt;*/ 0, /* configure later, i2csar;*/ 0x4620, /* master tx mode, */ /* i2c runs free, */ /* 8-bit data + NACK */ /* no repeat mode */ (75-1), /* 4MHz clock, i2cpsc */ }; void _IIC_write(I2C_Handle hI2C, Uint8 devAddress, Uint32 subAddress, Uint8 *data, Uint16 numBytes ) { Int i; I2C_Config prevIICConfig; /* make sure handle is valid */ if(hI2C == INV) { return; } /* Wait until bus is free */ while (I2C_bb(hI2C)); /* save old settings */ I2C_getConfig(hI2C, &prevIICConfig); /* set I2C mode register */ I2C_RSETH(hI2C, I2CMDR, EVM642VIDEOIIC_Config.i2cmdr); /* set I2C imr register */ I2C_RSETH(hI2C, I2CIMR, EVM642VIDEOIIC_Config.i2cimr); /* configure the I2C slave address register */ I2C_RSETH(hI2C, I2CSAR, devAddress); /* set I2C count register */ I2C_RSETH(hI2C, I2CCNT, numBytes + 1); /* write the sub address */ I2C_RSETH(hI2C, I2CDXR, subAddress); /* Generate start condition */ I2C_start(hI2C); I2CDELAY(DELAY_TIME); /* write the data */ for(i = 0; i < numBytes; i ++) { while(!I2C_xrdy(hI2C)); I2C_writeByte(hI2C, *data ++); I2CDELAY(DELAY_TIME); } /* Generate stop condition */ I2C_sendStop(hI2C); I2CDELAY(DELAY_TIME); /* Wait until bus is free */ while (I2C_bb(hI2C)); I2CDELAY(DELAY_TIME); /* now restore the previous I2C settings */ /* set I2C mode register */ I2C_RSETH(hI2C, I2CMDR, prevIICConfig.i2cmdr); /* set I2C imr register */ I2C_RSETH(hI2C, I2CIMR, prevIICConfig.i2cimr); /* configure the I2C slave address register */ I2C_RSETH(hI2C, I2CSAR, prevIICConfig.i2csar); /* set I2C count register */ I2C_RSETH(hI2C, I2CCNT, prevIICConfig.i2ccnt); I2CDELAY(DELAY_TIME); } Cheers mark-r -- "Let's meet the panel. You couldn't ask for four finer comedians - so that answers your next question..." -- Humphrey Lyttleton
Reply by ●April 4, 20052005-04-04
Thanks for your answer Mark. I've already seen this code but thanks anyway. I even contacted TI support but they only repeated what it is said on their datasheets! So I'll try to see how it really works now that i have access to the "workstation"! Mark Robinson <mark@simsol.co.uk> wrote in message news:<424BFDD4.E8967F34@simsol.co.uk>...> phuture_project wrote: > > I'm using the TMS320DM642 and need to configure the registers of a > > video decoder thanks to the I2C module. > > Don't know if it helps, but since no-one else has replied, this is > the code that TI use to talk to the SAA7115 on the DM642 EVM - > > #define I2CDELAY(iterations) { \ > volatile Int j; \ > for(j = 0; j < iterations; j ++); \ > } > #define DELAY_TIME 1000 > > static const I2C_Config EVM642VIDEOIIC_Config = { > 0, /* master mode, i2coar; */ > 0, /* no interrupt, i2cimr; */ > (20-5), /* scl low time, i2cclkl; */ > (20-5), /* scl high time,i2cclkh; */ > 1, /* configure later, i2ccnt;*/ > 0, /* configure later, i2csar;*/ > 0x4620, /* master tx mode, */ > /* i2c runs free, */ > /* 8-bit data + NACK */ > /* no repeat mode */ > (75-1), /* 4MHz clock, i2cpsc */ > }; > > void _IIC_write(I2C_Handle hI2C, > Uint8 devAddress, > Uint32 subAddress, > Uint8 *data, > Uint16 numBytes > ) > { > Int i; > I2C_Config prevIICConfig; > > /* make sure handle is valid */ > if(hI2C == INV) { > return; > } > /* Wait until bus is free */ > while (I2C_bb(hI2C)); > /* save old settings */ > I2C_getConfig(hI2C, &prevIICConfig); > /* set I2C mode register */ > I2C_RSETH(hI2C, I2CMDR, EVM642VIDEOIIC_Config.i2cmdr); > /* set I2C imr register */ > I2C_RSETH(hI2C, I2CIMR, EVM642VIDEOIIC_Config.i2cimr); > /* configure the I2C slave address register */ > I2C_RSETH(hI2C, I2CSAR, devAddress); > /* set I2C count register */ > I2C_RSETH(hI2C, I2CCNT, numBytes + 1); > /* write the sub address */ > I2C_RSETH(hI2C, I2CDXR, subAddress); > /* Generate start condition */ > I2C_start(hI2C); > I2CDELAY(DELAY_TIME); > /* write the data */ > for(i = 0; i < numBytes; i ++) { > while(!I2C_xrdy(hI2C)); > I2C_writeByte(hI2C, *data ++); > I2CDELAY(DELAY_TIME); > } > /* Generate stop condition */ > I2C_sendStop(hI2C); > I2CDELAY(DELAY_TIME); > /* Wait until bus is free */ > while (I2C_bb(hI2C)); > I2CDELAY(DELAY_TIME); > /* now restore the previous I2C settings */ > /* set I2C mode register */ > I2C_RSETH(hI2C, I2CMDR, prevIICConfig.i2cmdr); > /* set I2C imr register */ > I2C_RSETH(hI2C, I2CIMR, prevIICConfig.i2cimr); > /* configure the I2C slave address register */ > I2C_RSETH(hI2C, I2CSAR, prevIICConfig.i2csar); > /* set I2C count register */ > I2C_RSETH(hI2C, I2CCNT, prevIICConfig.i2ccnt); > I2CDELAY(DELAY_TIME); > } > > Cheers > > mark-r
Reply by ●April 4, 20052005-04-04
phuture_project wrote:> > I've already seen this code but thanks anyway.Ahh well, never mind. Let me know if you find out anything useful (email address works), because I'm going to have to do some I2C work soon, too. Cheers mark-r -- "Let's meet the panel. You couldn't ask for four finer comedians - so that answers your next question..." -- Humphrey Lyttleton
Reply by ●April 5, 20052005-04-05
Mark Robinson <mark@simsol.co.uk> wrote in message news:<4251072C.4B6D963B@simsol.co.uk>...> phuture_project wrote: > > > > I've already seen this code but thanks anyway. > > Ahh well, never mind. Let me know if you find out anything useful > (email address works), because I'm going to have to do some I2C work > soon, too. > > Cheers > > mark-rOk! No problem!
Reply by ●April 5, 20052005-04-05
I hope you have seen the spru175a, there they have the complete flowcharts for polling mode and interrupt driven mode. DM642 has some problem in i2C silicon Do remember these when coding Please see this doc. http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=sprz196i&fileType=pdf I2C: Bus Busy Bit Does Not Reflect the State of the I2C Bus When the I2C is in Reset I2C: Addressed-As-Slave (AAS) Bit is not Cleared Correctly Hope this information helps you . Good luck guys
